3v4l.org

run code in 300+ PHP versions simultaneously
<?php $false = "a"; $v = true; echo (string) ${!$v}, PHP_EOL; echo !isset(${!$v});
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.31, 8.2.0 - 8.2.27, 8.3.0 - 8.3.15, 8.4.1 - 8.4.2
Warning: Undefined variable $ in /in/8j971 on line 5 1
Output for 5.0.4 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.31, 7.4.0 - 7.4.33
Notice: Undefined variable: in /in/8j971 on line 5 1
Output for 7.3.32 - 7.3.33
1
Output for 4.3.10 - 4.3.11, 4.4.0 - 4.4.9, 5.0.2 - 5.0.3
Notice: Undefined variable: in /in/8j971 on line 5 1
Output for 4.3.0 - 4.3.9, 5.0.0 - 5.0.1
Notice: Undefined variable: in /in/8j971 on line 5 Notice: Use of undefined constant PHP_EOL - assumed 'PHP_EOL' in /in/8j971 on line 5 PHP_EOL1

preferences:
48.29 ms | 411 KiB | 5 Q